Limiting and stopping device.



B. E. MARSHALL. LIMITING AND STOPPING DEVICE. APPLICATION rnnn snrmzm 1013.

1,1 06,574. Patented Aug. 11, mm

2 SHEEN-SHEET l.

wfinassas lnugm/or B. B. MARSHALL. LIMITING AND STOPPING DEVICE.

APPLICATION EILED SEPT. 22, 1913- 574 Patented Aug. 11, 1914. z sums-sum: 2.

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BRUNO EWARD MARSHALL, 0F WILLIAMS, ARIZONA, ASQIGNOR 0F ONE-FOURTH T0 FRANK A. BALDWIN AND ONE-FOURTH TO VICTOR M. TUTHILL, BOTH OF GRAND RAPIDS, MICHIGAN, DOING BUSINESS UNDER THE FIRM-NAME BALDWIN, TUT- HILL AND BOLTON.

LIMITING AND STOPPING DEVICE.

Patented Aug. i iota.

hereby declare the fol owing to be a full,

clear, and exact description of the invention,

such as will enable others skilled inthe artj to which it appertains to make and use the same.

My invention relates to improvements in limiting and stopping devices for the feed mechanism of automatic machinery and particularly to such machinery as automatic and its object will stop the feeding mechanism-of the machine after it has traveled a predetermined distance, to provide a device which will be simple in construction'and operation, and to provide ful features hereinafter more fully described and particularly pointed out in the claims.

In certain classes of wood working machinery, such as planers, etc., in which more than one knife is attached to a rapidly rotating head, it is necessary that these knives be exactly the same weight so, that the head with the knives attached thereto will be perfectly balanced and will run smoothly 'when-rotating at a high speed. It is, there-' fore, necessarywhen the knives are sharpened, to grind exactly the same amount of material from each. knife so that they will remain exactly-the same weight. Theusual,

inethodofmaintaining the knives the same weight has been to carefully weigh them :after they have been sharpened,fand should one knife be heavier than "the otheiy-itis again placed in the grinding machine andv sufficient material ground away to mak'eit exactly balance the lighter knifetYThi's method was objectionable because itv was often necessary to replace the knife in the grinding machine several times before an. exact balance of the knives 'was'obt'ained' My invention overcomes this objectionablemethod by providing automatic stopping means on the feeding mechanism 'of the; grinding machine,'by-which the said, feed-:

7 -ing mechanism is thrown out of operation the same with other new and use-,-

after it has traveled forward a certain predetermined; distance and consequently by ad]ust1ng this stopping device the same for each knife the same amount of material will be ground away from each of the knives, and they will retain their uniform weight.

,60 The preferred construction and arrange ment of this stopping device is clearly shown 1n the accompanying drawings in which I Figure 1 is a plan view ofan automatic knifegrinding machine with .myvimproved stopping device applied thereto; Fig.- 2 is a front elevation of the same; Fig. 3 is an enlarged transverse section of a portion of 2 the grinding machine showing the stopping device 1n operative position; Fig. 1 is an enlarged plan, partially in section of a portion of the machine and the stopping device;

and Fig. 5 is an enlarged transverse section of the stopping device showing thefeeding pawl lifted out of engagement with the ratchet wheel.

Like numbers refer to like parts in all of the figures. a

1 represents the frame of a rinding machine which has a grinding w eel 2 a-nd a reclprocating carriage 3. A tilting table 4: 18 located before the grinding wheel and is supported at its respective ends by trun- .1110I1S ournaled ,in supports 5, which are movable transversely of. the carriage on ways 6. These supportsfi are automatically moved toward or from the grindingwheel by means of feed screws 7 and these feed screws are in turn rotated from ashaft 8 through the worm" gears 9 'an'd '10. fl lhe shaft 8 is rotated step by 'step'at' the end of each alternate reciprocation of the carriage 3'by means of a ratchet whel ll attached to the shaft and engaged by a pawl 12 on one. end'of a lever '13. The opposite end of this lever engages a stationary cam 14 at the en'd'of each alternate stroke of the carpage and is moved thereby which causes a partial rotation of the shaft 8, and when the lever 13 is released as the carriage, moves on its return stroke, it is returnedfto normal position by means'of a; spring 15.

- The stoppinx device is for the purpose of raising the pawl 12 fromengagement ,with

the ratchet wheeljl'l, afterth'eztabl'e' 4 has been: moved a predetermined distance toward the grinding wheel and itgcomprises a, star wheel 16 journaled in a housing 17 20 of the star wheel and so located that after and provided with a spring actuated detent 18, which prevents inadvertent rotation of the wheel. A pin 19 projecting from the face of the ratchet wheel 11 is so arranged that it will engage one tooth of the star wheel at each rotation of the ratchet wheel and rotate the star wheel the space of one tooth. A lifting lever 20 is pivotally attached at one end to the side of the housing 17 and its free end is adapted to engage a pin 21 which projects from the pawl 12. A cam 22 is provided on the shaft 23 of the star wheel and rotates with said wheel.

This cam engages a projection 20 on the lifting lever, and at a certain position of the star wheel the cam raises the lever 20 and lifts the pawl 12 out of engagement with the ratchet wheel 11. A blank space 16 having no teeth is provided on the periphery the lever 20 has been raised by the cam 22, the pin 19 will move freely opposite the said blank space at each rotation of the ratchet wheel and will have no effect upon the star 25 wheel. This permits manual adjustment of the machine by rotating the shaft 8 by the hand wheel 8 without aifectin the position of the star wheel 16. To facilitate adjusting the' stopping device, numerals are stamped on the face of the star Wheel opposite each of the teeth thereon, and these numerals appear through an aperture 24 in the housing 17. A knob 25 is also provided on the shaft 23 so'vthat the star wheel may -be adjusted to the desired position when setting the device.

The operation of the device is as follows :The operator attaches one knife of a set to the table 4:, and then rotates the 40 shaft 8 manually by means of the hand wheel 8 which moves the table forward.

until the knife 25 engages the grinding wheel 2. The machine is then set in motion and the knife is ground sufficiently to sharpen it. Duringthis operation the shaft wheel, and the star wheel is then manually 00 again put in operation.

rotated until the numeral thereon representing the number of teeth which were moved during the former operation appears through the opening 24; and the machine is The above described operation is repeated until the star wheel has been rotated the number of teeth indicated by the numeral at which it was set, at which point the cam 22 will engage the projection 20 on the lever 20 and raise the same, lifting the pawl 12 out of engagement with the ratchet wheel whereupon the operation of the feeding mechanism is arrested and the grinding of the knife ceases. Each subsequent knife in the-Set is submitted to the same process and consequently they are uniformly ground and remain the same weight and balance.

What I claim is 1. In combination with feeding mechanism having both automatic means and manual means for separately operating the same, means for automatically and wholly disengaging the automatic means from the feed mechanism at a predetermined point in its operation, whereby the feed mechanism may be manually operated without operating the automatic means.

2. In combination with feed mechanism having both pawl and ratchet means and manual means for separately operating the same, means for automatically disconnecting the pawl from the ratchet at a predetermined point in its operation and automatic means for disconnecting the feed mechanism and said automatic means to permit independent manual operation of the feed mechanism without affecting the automatic means.

3. In combination with feeding mechanism having both pawl and ratchet mechanism and manual meansfon separately operatin I pawl rom the ratchet, astar wheel rotated by the ratchet wheel, and operating the lever, and means for siinultaneousl dlSCOII- necting the star wheel and'theratc et when the lever disconnects the pawl, whereby the feed mechanism may be manually 0 erated without affecting the automatic mec anism.

4. In combination with a feeding mechanism driven by a pawl and ratchet of a Wheel rotated by the said ratchet, a cam rotated by thewheel and a lever moved by the cam to disengage the pawl from the ratchet.

5. In combination with feeding mechanism driven by a pawl and ratchet wheel of a stopping device, comprising a star wheel, a pin on the ratchet wheel to engage the star wheel to actuate the same, a cam in fixed relation to the star wheel, a pivoted lever actuated by the cam and a pin projecting from the pawl'and engaged by the lever whereby the pawl is disengaged from the ratchet at a. predetermined point.

6. In combination with a feeding mechanism driven by a pawl and ratchet wheel, of astopping device comprising a pin projecting from the pawl, a pivotedleverto engage the pin, a cam to actuate the lever, a star wheel to rotate the cam, said star wheel having a blank space on its periphery arranged to be opposite the ratchet wheel when the lever is raised by the cam, and a the same, a lever to disconnect the pin projecting from the ratchet wheel to engage the star wheel to actuate the same.

7. In combination with a feeding mechanism driven by a pawl and ratchet wheel of a stopping device comprising a star wheelrotatable Within a housing, and having a blank space on its periphery, a pin projecting from the ratchet wheel to engage the star wheel to actuate the same, a cam in fixed relation to the star wheel a pivoted lever raised by the cam when the lilank space on the star wheel is moved opposite the ratchet wheel, a .pin prcjecting from the 

